EP0133802A1
Expired / Lapsed
EP
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A rotary transformer
Assignee: TDK Corp
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Filing: 1984-08-03
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Granted: —
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Expires: 2004-08-03
Abstract
Abstract A multi-channel rotary transformer includes a pair of disc cores 50, 60, 70, 80, one of which is rotatably mounted and the other of which is fixed. Each disc core 50, 60, 70, 80 having a plurality of grooves 16 for accepting coils, and holes 30 opening into the grooves 16 for taking leads of the coils. Such a structure is improved by providing a dummy second hole 38 positioned symmetrically with each of the first holes 30 so that the disc cores 50, 60, 70, 80 are statically and dynamically balanced. Preferably portions 44 of annular projections 28 between two adjacent annular grooves 16 adjacent the holes 30 and 38 are recessed and this, in manufacture of a disc core from a ferrite material, leads to localised compression of the ferrite material which prevents cracking or breaking at that portion.
Inventors
- 👤 Takakazu Yamazaki
- 👤 Norio Ishida
- 👤 Satoshi Saito
- 👤 Hiroshi Sato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 09:43
CPC Classifications
H; H01; H01F; H01F38/00; H01F38/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
236 words
A multi-channel rotary transformer comprising a pair of identical disc cores (50, 60, 70, 80) which are mounted for relative rotation, each of the disc cores (50, 60, 70, 80) comprising a number of concentric annular grooves (16 1 , 16 2 , ...16 5 ) provided on the facing surfaces for accommodating coils (18, 24), each of the annular grooves (16 1 , 16 2 , ...16 5 ) being concentric with the centre of the disc core (50, 60, 70, 80) and having a first hole (30 1 , 30 2 , ...30 5 ) for lead wires from the coil, characterised in that each of the annular grooves (16 1 , 16 2 , ...16 5 ) of each disc core (50, 60, 70, 80) has a second hole (38 1 , 38 2 , ...38 5 ) of the same configuration as the first hole (30 1 , 30 2 , ...30 5 ), the second hole (38 1 , 38 2 , ...38 5 ) being positioned diammetrically opposite the first hole (30 1 , 30 2 ...30 5 ), and the first (30 1 , 30 2 , ...30 5 ) and second (38 1 , 38 2 , ...38 5 ) holes being symmetrically located with regard to the centre of the disc core (50, 60, 70, 80) so that the disc core (50, 60, 70, 80) is balanced.
Claim 2
Dependent Claim
236 words
A multi-channel rotary transformer comprising a pair of identical disc cores (50, 60, 70, 80) which are mounted for relative rotation, each of the disc cores (50, 60, 70, 80) comprising a number of concentric annular grooves (16 1 , 16 2 , ...16 5 ) provided on the facing surfaces for accommodating coils (18, 24), each of the annular grooves (16 1 , 16 2 , ...16 5 ) being concentric with the centre of the disc core (50, 60, 70, 80) and having a first hole (30 1 , 30 2 , ...30 5 ) for lead wires from the coil, characterised in that each of the annular grooves (16 1 , 16 2 , ...16 5 ) of each disc core (50, 60, 70, 80) has a second hole (38 1 , 38 2 , ...38 5 ) of the same configuration as the first hole (30 1 , 30 2 , ...30 5 ), the second hole (38 1 , 38 2 , ...38 5 ) being positioned diammetrically opposite the first hole (30 1 , 30 2 ...30 5 ), and the first (30 1 , 30 2 , ...30 5 ) and second (38 1 , 38 2 , ...38 5 ) holes being symmetrically located with regard to the centre of the disc core (50, 60, 70, 80) so that the disc core (50, 60, 70, 80) is balanced.
Claim 3
Dependent Claim
34 words
A rotary transformer according to claim 1, wherein each of the first (30 1 , 30 2 ...30 5 ) and second (38 1 , 38 2' ... 38 5 ) holes is cylindrical.
Claim 4
Dependent Claim
104 words
A rotary transformer according to claim 1 or 2, wherein a recess (44 1 , 44 2 , ... 44 4 ) is provided in each annular projection (28 2 , 28 3 , ... 28 5 ) located between two adjacent annular grooves (16 1 , 16 2 , ... 16 5 ) the recess (44 1 , 44 2 , ... 44 4 ) being located adjacent a hole ( 30 1 , ....30 5 ; 38 1 , ....38 5 ) and extending across the entire width of the annular projection (28 2 , 28 3 , ... 28 5 ).
Claim 5
Dependent Claim
105 words
A rotary transformer according to the claim 3, wherein the recess (44 1 , 44 2 ...44 4 ) is substantially rectangular in shape, the depth (D 1 ) of the recess (44 1 , 44 2 ...44 4 ) being equal to or lower than that (D 2 ) of the annular grooves (161, 16 2 , ...16 5 ) and the width (W) of the recess (44 1 , 44 2 ...44 4 ) being equal to the diameter of the first (30 1 , 30 2 , ...30 5 ) and second (38 1 , 38 2 , ...38 5 ) holes.
References Cited (Backward Citations)
US4293884A
Cited
GB2111315A
Cited
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